Preponderance of Late-spiking Neurons in Rat Lateral Amygdala

Whole-cell recordings from rat lateral amygdala (LA) revealed two populations of principal neurons, that have similar pyramid-like morphologies but differing in firing pattern: late-spiking (LS, 66%) and regular-spiking (RS, 34%). The presence of large numbers of LS neurons arguably supports recent suggestions that the LA should be considered to be a functional extension of perirhinal cortex

Rilevanza della tipologia e durata dell'allungamento muscolare e possibili applicazioni cliniche

La flessibilità è una componente chiave per la salute, pertanto il mantenimento di un appropriato livello di flessibilità è fondamentale per l’espletamento delle attività della vita quotidiana. Per migliorare la flessibilità, può essere usato lo stretching, una tecnica che agisce sull’ unità muscolo-tendinea che promuove l’arco di movimento(ROM). Varie tipologie di stretching sono conosciute, ma poco si sa su quale sia la strategia più idonea, o se vi sia una relazione tra una specifica tipologia di stretching ed il tempo ottimale necessario ad indurre un adattamento a lungo termine nel ROM. Per cui questa tesi di dottorato si è prefissa di capire la relazione che sussiste tra la tipologia di stretching a lungo termine ed il ROM e secondariamente vedere se anche il volume è correlato ad incrementi nel ROM. 23 Articoli scientifici sono stati inclusi nella sintesi qualitativa. Tutte le tipologie di stretching mostrano incrementi nel miglioramento dell’arco di movimento dopo un periodo di intervento, tuttavia solo i protocolli statici mostrano miglioramenti significativi (p<0.05) quando paragonati ai protocolli balistici o PNF. Il tempo speso nell’allungamento muscolare sembra fondamentale nel determinare incrementi del ROM quando lo stretching è applicato per più di 5 minuti a settimana, mentre il tempo speso a fare stretching per singola sessione non sembra determinante nell’indurre adattamenti muscolari. Anche la frequenza settimanale è associata a positivi incrementi del ROM. I dati sembrano indicare che eseguire sessioni di stretching per almeno 5 volte a settimana per almeno 5 minuti complessivamente, applicando protocolli di stretching statico, siano la strategia più idonea per promuovere l’incremento del ROM

RNNs Implicitly Implement Tensor Product Representations

Recurrent neural networks (RNNs) can learn continuous vector representations of symbolic structures such as sequences and sentences; these representations often exhibit linear regularities (analogies). Such regularities motivate our hypothesis that RNNs that show such regularities implicitly compile symbolic structures into tensor product representations (TPRs; Smolensky, 1990), which additively combine tensor products of vectors representing roles (e.g., sequence positions) and vectors representing fillers (e.g., particular words). To test this hypothesis, we introduce Tensor Product Decomposition Networks (TPDNs), which use TPRs to approximate existing vector representations. We demonstrate using synthetic data that TPDNs can successfully approximate linear and tree-based RNN autoencoder representations, suggesting that these representations exhibit interpretable compositional structure; we explore the settings that lead RNNs to induce such structure-sensitive representations. By contrast, further TPDN experiments show that the representations of four models trained to encode naturally-occurring sentences can be largely approximated with a bag of words, with only marginal improvements from more sophisticated structures. We conclude that TPDNs provide a powerful method for interpreting vector representations, and that standard RNNs can induce compositional sequence representations that are remarkably well approximated by TPRs; at the same time, existing training tasks for sentence representation learning may not be sufficient for inducing robust structural representations.Comment: Accepted to ICLR 201

The effects of climate change on the competitive ability of Impatiens glandulifera relative to a native plant community

Impatiens glandulifera is one of the most widespread invasive plant species in the UK. This thesis explores how invasive plants such as I. glandulifera utilise ‘plant-soil feedbacks’ to alter the biotic and abiotic components of soil in order to facilitate invasions, and how this phenomenon responds to climate change. Native plants commonly co-occurring with I. glandlifera, alongside the invader itself, were grown in two experiments simulating different effects of climate change. The first investigated the effects of water availability, with I. glandulifera and a native community grown in a range of watering treatments simulating different water availability scenarios under climate change. The second experiment explored the temperature effects of climate change, and consisted of two phases. In the first, exclusive communities of I. glandulifera or native plants were grown in two growth chambers simulating present-day and warmer future temperatures. In the second, I. glandulifera and a native community were grown in those same pots in the chambers, allowing the effects of invader plant-soil feedbacks to be observed. Plant physical parameters were recorded in both studies, with results confirming that 1) I. glandulifera consistently shows a greater competitive ability than native species, even under watering treatments that negatively affect its growth, and 2) that I. glandulifera exhibits a positive plant-soil feedback effect, and that this effect can complement the warming effects of climate change to negatively affect a native community. Finally, soil extracts from the temperature experiment had their DNA extracted and sequenced for metabarcoding of the soil bacterial and fungal communities, further investigating the drivers of invasive species plant-soil feedbacks. This analysis exhibited potential effects of I. glandulifera soil conditioning on microbial communities, as well as microbial responses to increased temperature under climate change. The findings of these three studies have important implications for future efforts to manage invasive species

Non-collinear interaction of photons with orbital angular momentum

We elucidate the consequences of a phase-matching theory that describes second-harmonic generation of two non-collinear incident light beams that carry orbital angular momentum (OAM). More specifically, the two incident beams generate a third that, depending on the incident OAM, may experience a significantly smaller conversion efficiency in comparison to that based on the conventional phase-matching theory. This is the case even for incident angles substantially less than those required for non-conservation of OAM in the nonlinear interaction. Experiments are performed under different conditions and are in excellent agreement with the theory. Our results have implications beyond the specific case studied here of second-harmonic generation, in particular for parametric down-conversion of photons.Comment: 6 pages, 4 figure

Authoritarian Diffusion and Cooperation within International Organisations: Legal Harmonisation of Internet Sovereignty Policies within the Countries of the Shanghai Cooperation Organisation

This paper explores the concept of "internet sovereignty" as developed and endorsed by the member states of the Shanghai Cooperation Organisation (SCO). First, the concept is shown to have developed as a synthesis between the restrictive Chinese internet governance model based on the "Golden Shield" and Russian conceptions of national "information spheres". Research then shows how this "sovereignty" model serves to legitimise refocusing internet governance around the state, allowing for stricter controls on internet access, content, data, and infrastructure in authoritarian contexts. Using causal process tracing, this paper shows that the SCO supports the transfer of digital policy between members based on this normative "sovereignty" model, the alignment of states with the legalised form of this model in institutional documentation, and the transfer of the legitimising "Three Evils" narrative frame. This shows that regional organisations can provide a significant platform for authoritarian learning, which, when successful, helped the regimes of the SCO to find policies to expand and stabilise their control over the digital realm

Determination of a strength index for upper body local endurance strength in sedentary individuals: a cross sectional analysis

A range of balance between flexor and extensor muscles is fundamental in order to prevent pathologies caused by bad postures or to ensure health of the joint as a measure of prevention of overtraining in specific muscle groups. Therefore, the aim of this study is to examine the ratio between "pulling" and "pushing" strength in sedentary individuals. 212 healthy participants, of both genders (139 male and 73 female; age 32 \ub1 13.3 years, weight 70.2 \ub1 14.1 kg, height 173 \ub1 9 cm) were retained for investigation. Strength was assessed through a new methodology: Pulling through a lat-pulldown test while pushing strength through a chest-press test. Both tests were performed to exhaustion with an overload of 30 % of each participants bodyweight. Such method aims to prevent excessive overloads in sedentary individuals. Pearson's correlations and a t test to assess differences were analyzed. Subsequently, the ratio for both genders of pulling and pushing local endurance strength was assessed by means. A mean number of 57 repetitions was shown with the lat-pulldown while 34 repetition with the chest press. A correlation of 0.42 has been found between the number of repetitions of the two tests. A significant difference (p < 0.001) was found between such performances. No correlation was found between the strength measures and the anthropometric parameters of the participants. The lat machine to chest press ratio was 1.36:1 for male while 2.69:1 for female. The results indicate that sedentary participants have higher pulling rather than pushing local endurance strength. Such ratio should be considered as a normative value when starting to perform exercise protocols. Resistance training should be performed in order to improve strength measures of the weaker muscles and reduce such ratio

International education in Hong Kong: paradoxes in intercultural communication, adaptation, and acculturation strategies

Countries in East Asia that have traditionally been sources of international students are now being regarded highly desirable destinations for higher education. Yet little is known about the experiences of international students in East Asia as most research focuses on those in the Anglophone West. In this study, we explored the intercultural communication, adaptation, and acculturation strategies of international students in Hong Kong. We conducted in-depth interviews with international students from other Asian countries (n=14) and Western countries (n=10). Our findings identified a paradox between the international students’ enthusiasm to engage with students from other backgrounds and a lack of interactions and friendships with local students. First, cultural and language differences were perceived to create a wall separating them from the local students, inhibiting a cosmopolitan learning environment. Second, international students primarily identified with peers with a shared national or cultural background who could provide a readymade community. Third, international students often reported sociocultural adaptation challenges and feelings of being outsiders, potentially exacerbating psychological adaptation problems. Based on our findings, we propose a framework depicting interactive and responsive relationships among intercultural communication, adaptation, and acculturation. We conclude by putting forward initiatives aimed at realising the benefits of international student mobility for both international and local students

Experimental characterization of nonlocal photon fluids

Quantum gases of atoms and exciton-polaritons are now well-established theoretical and experimental tools for fundamental studies of quantum many-body physics and suggest promising applications to quantum computing. Given their technological complexity, it is of paramount interest to devise other systems where such quantum many-body physics can be investigated at lesser technological expense. Here we examine a relatively well-known system of laser light propagating through thermo-optical defocusing media: based on a hydrodynamic description of light as a quantum fluid of interacting photons, we investigate such systems as a valid room-temperature alternative to atomic or exciton–polariton condensates for studies of many-body physics. First, we show that by using a technique traditionally used in oceanography it is possible to perform a direct measurement of the single-particle part of the dispersion relation of the elementary excitations on top of the photon fluid and to detect its global flow. Then, using a pump-and-probe setup, we investigate the dispersion of excitation modes of the fluid: for very long wavelengths, a sonic, dispersionless propagation is observed that we interpret as a signature of superfluid behavior